1. Field of the Invention
The present invention relates to the structure and utilization method of a semiconductor manufacturing apparatus of a single wafer type, which is also a semiconductor manufacturing apparatus of a vacuum-load-lock type, capable of efficiently processing wafers in succession.
2. Description of the Related Art
The film formation temperatures in the reaction chambers of general CVD apparatuses are approx. 400° C. As a result, the wafer temperature after a backfill of the load lock chamber (a step to restore the load lock chamber (IOC) to the atmospheric pressure from a vacuum state via introduction of N2), which occurs following film formation, is still high, or around 200° C. In conventional apparatuses, therefore, wafers must be kept in the load lock chamber, in a dedicated cooling chamber or in other location until the hot wafers cool down to temperatures acceptable to the wafer carrier (approx. 100° C.). This limits the wafer transfer speed and consequently reduces the throughput.
One measure to address this problem is installing a cooling stage inside the mini environment that accommodates the transfer robot. However, it will increase the footprint as a result of a larger mini environment. Another potential solution is to provide a separate cooling fan or utilize cooling water in order to promote the cooling of wafers inside the mini environment. However, this is a costly approach for obvious reasons.